Search found 51 matches

by Michael Cheng 1C
Fri Mar 16, 2018 6:38 pm
Forum: *Electrophilic Addition
Topic: nucleophile and electrophile reactions
Replies: 6
Views: 1088

Re: nucleophile and electrophile reactions

do we need to know nucleophiles and electrophiles for the final? What is the difference between them?
by Michael Cheng 1C
Fri Mar 16, 2018 6:37 pm
Forum: *Electrophiles
Topic: what is going to be on the final? [ENDORSED]
Replies: 12
Views: 841

Re: what is going to be on the final? [ENDORSED]

does anyone know if ochem will be huge on the final
by Michael Cheng 1C
Fri Mar 16, 2018 6:36 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: porous disk
Replies: 3
Views: 145

Re: porous disk

how do you know when to use a porous disk?
by Michael Cheng 1C
Sat Mar 10, 2018 3:55 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Pseudo Rate Law [ENDORSED]
Replies: 3
Views: 169

Re: Pseudo Rate Law [ENDORSED]

Are there any homework problems where we use the pseudo rate law?
by Michael Cheng 1C
Sat Mar 10, 2018 3:50 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Arrhenius Equation [ENDORSED]
Replies: 7
Views: 260

Re: Arrhenius Equation [ENDORSED]

how would you find A (frequency factor) in the Arrhenius Equation?
by Michael Cheng 1C
Sat Mar 10, 2018 3:39 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: formula on 15.61
Replies: 3
Views: 158

Re: formula on 15.61

or you can make y2 = ln(k) and y1 = ln(k') as the book did it.
but you should get the same answer either way
by Michael Cheng 1C
Sat Mar 10, 2018 3:37 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: formula on 15.61
Replies: 3
Views: 158

Re: formula on 15.61

I used point slope form. If ln(k) = -(Ea/R)(1/T) + ln(A), where y = ln(k), m = -(Ea/R) , x = (1/T), and b = ln(A)

point slope form is (y2-y1) = m(x2-x1)
You can substitute (lnk' - lnk) = -(Ea/R)(1/T' - 1/T)
and then distribute the negative to get:
(lnk' - lnk) = (Ea/R)(1/T - 1/T')
by Michael Cheng 1C
Sat Mar 03, 2018 10:10 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Kinetics vs Thermodynamics
Replies: 7
Views: 294

Re: Kinetics vs Thermodynamics

If a reaction is thermodynamically stable, will it automatically be kinetically stable?
by Michael Cheng 1C
Sat Mar 03, 2018 10:07 pm
Forum: Zero Order Reactions
Topic: Zero order common?? [ENDORSED]
Replies: 5
Views: 198

Re: Zero order common?? [ENDORSED]

is it possible to have a pseudo 0 order reaction
by Michael Cheng 1C
Sat Mar 03, 2018 10:06 pm
Forum: First Order Reactions
Topic: Pseudo-First Order Reaction [ENDORSED]
Replies: 4
Views: 200

Re: Pseudo-First Order Reaction [ENDORSED]

what is the difference between k' and k?
by Michael Cheng 1C
Sun Feb 25, 2018 4:54 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Instantaneous Rate
Replies: 4
Views: 248

Re: Instantaneous Rate

Why are we only looking at initial rate of reaction in this chem class?
by Michael Cheng 1C
Sun Feb 25, 2018 4:47 pm
Forum: First Order Reactions
Topic: Reaction order
Replies: 4
Views: 192

Re: Reaction order

is it possible to find reaction order for more than two products or reactants?
by Michael Cheng 1C
Sun Feb 25, 2018 4:39 pm
Forum: General Rate Laws
Topic: Reaction Rate and Spontaneity
Replies: 5
Views: 357

Re: Reaction Rate and Spontaneity

can a nonspontaneous and spontaneous reaction have the same reaction rate?
by Michael Cheng 1C
Sun Feb 18, 2018 11:54 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: notation for galvanic cell
Replies: 2
Views: 101

Re: notation for galvanic cell

is there a notation for concentration cells?
by Michael Cheng 1C
Sun Feb 18, 2018 11:47 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic vs Concentration
Replies: 3
Views: 136

Re: Galvanic vs Concentration

can someone give me an example of concentration cell? Also, are the calculations basically the same equations for the two cells?
by Michael Cheng 1C
Sun Feb 18, 2018 11:44 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Inert Conductor
Replies: 3
Views: 87

Re: Inert Conductor

So is platinum one of the common inert conductors?
by Michael Cheng 1C
Sun Feb 11, 2018 12:51 am
Forum: Balancing Redox Reactions
Topic: Salt Bridges
Replies: 14
Views: 379

Re: Salt Bridges

does a porous disk and salt bridge have the same purpose?
by Michael Cheng 1C
Sun Feb 11, 2018 12:49 am
Forum: Balancing Redox Reactions
Topic: Oxidation vs. reduction
Replies: 8
Views: 224

Re: Oxidation vs. reduction

How can you tell which reaction to flip when doing the redox problems?
by Michael Cheng 1C
Sun Feb 11, 2018 12:44 am
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Standard Cell Potential
Replies: 4
Views: 431

Re: Standard Cell Potential

I am confused as to the difference between cell potential and reduction potential. Can someone explain it to me? Thanks
by Michael Cheng 1C
Sun Feb 04, 2018 1:30 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: deltaG at equilibrium
Replies: 5
Views: 135

Re: deltaG at equilibrium

How will you know using the Gibbs Free energy which way the reaction will proceed if its not at equilibrium?
by Michael Cheng 1C
Sun Feb 04, 2018 1:27 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy -/+
Replies: 4
Views: 144

Re: Gibbs Free Energy -/+

so spontaneous reaction is associated with - Gibbs Free Energy?
by Michael Cheng 1C
Sat Jan 27, 2018 10:05 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Reversible Vs Irreversible
Replies: 3
Views: 116

Re: Reversible Vs Irreversible

So then why is temperature not constant in irreversible reactions?
by Michael Cheng 1C
Sat Jan 27, 2018 9:59 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Reversible isothermal expansion
Replies: 4
Views: 112

Re: Reversible isothermal expansion

So will reversible expansion always be at constant temperature?
by Michael Cheng 1C
Sat Jan 27, 2018 9:58 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Degeneracy
Replies: 4
Views: 167

Re: Degeneracy

Does degeneracy have any relation to the spontaneity of a reaction?
by Michael Cheng 1C
Fri Jan 19, 2018 6:03 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Difference between heat(q), internal energy(U), and enthalpy(H)
Replies: 4
Views: 1149

Re: Difference between heat(q), internal energy(U), and enthalpy(H)

So then, what is the difference between heat (q) and enthalpy (H)? more specifically the difference between q and deltaH
by Michael Cheng 1C
Fri Jan 19, 2018 5:59 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: the sign of q and w [ENDORSED]
Replies: 6
Views: 232

Re: the sign of q and w [ENDORSED]

so if w decreases, will the internal energy of the system increase or decrease?
by Michael Cheng 1C
Fri Jan 19, 2018 5:56 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: W=-(Pex)(deltaV)
Replies: 5
Views: 258

Re: W=-(Pex)(deltaV)

Wait, so is the work in perspective of the system?
by Michael Cheng 1C
Fri Jan 12, 2018 12:13 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.51
Replies: 3
Views: 146

Re: 8.51

so when finding the enthalpy of reaction, is it just the sum of enthalpy of formation of products - sum of enthalpy of formation of reactants?
by Michael Cheng 1C
Fri Jan 12, 2018 12:10 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.49
Replies: 5
Views: 198

Re: 8.49

What is the difference between internal energy and enthalpy?
by Michael Cheng 1C
Thu Jan 11, 2018 12:22 am
Forum: Phase Changes & Related Calculations
Topic: Enthalpy is a state property
Replies: 13
Views: 483

Re: Enthalpy is a state property

So would Heat be considered a state property or not?
by Michael Cheng 1C
Tue Dec 05, 2017 10:27 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Oxoacids
Replies: 1
Views: 127

Oxoacids

I am very confused on what an oxoacid is. Can someone explain what it is and its significance? Thank you
by Michael Cheng 1C
Tue Dec 05, 2017 10:25 am
Forum: Conjugate Acids & Bases
Topic: Different from Bronsted and Conjugate
Replies: 3
Views: 284

Re: Different from Bronsted and Conjugate

Is there a difference between Conjugate Bronsted acid/base and Conjugate Lewis acid/base?
by Michael Cheng 1C
Sun Dec 03, 2017 11:54 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted and Lewis acid definitions?
Replies: 3
Views: 249

Re: Bronsted and Lewis acid definitions?

Are lewis acids and bases the same as bronsted? Or are they different types of acids and bases?
by Michael Cheng 1C
Sun Dec 03, 2017 11:52 pm
Forum: Amphoteric Compounds
Topic: Amphiprotic [ENDORSED]
Replies: 5
Views: 473

Re: Amphiprotic [ENDORSED]

What is the difference between amphiprotic and amphoteric
by Michael Cheng 1C
Sat Nov 25, 2017 9:43 pm
Forum: Ideal Gases
Topic: Ideal Gas Law
Replies: 3
Views: 160

Re: Ideal Gas Law

What if one of the two assumptions are not met?
by Michael Cheng 1C
Sat Nov 25, 2017 9:41 pm
Forum: Ideal Gases
Topic: Partial pressure when calculating K
Replies: 4
Views: 328

Re: Partial pressure when calculating K

When do you use partial pressure versus concentration when finding equilibrium?
by Michael Cheng 1C
Sun Nov 19, 2017 9:16 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Understanding sigma and pi bonds?
Replies: 8
Views: 324

Re: Understanding sigma and pi bonds?

Do sigma and pi bonds apply to ligands and coordination compounds?
by Michael Cheng 1C
Sun Nov 19, 2017 9:14 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chelating Complexes
Replies: 5
Views: 232

Re: Chelating Complexes

I'm still confused as to the definition or function of a chelate is versus a regular ligand. What is the distinction between the two?
by Michael Cheng 1C
Sat Nov 11, 2017 12:38 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles [ENDORSED]
Replies: 3
Views: 164

Re: Bond Angles [ENDORSED]

how do we know the bond angles for trigonal bipyramidal? Do we need to memorize all the different angles?
by Michael Cheng 1C
Sat Nov 11, 2017 12:36 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Shape Memorization [ENDORSED]
Replies: 7
Views: 422

Re: Shape Memorization [ENDORSED]

What is the difference between trigonal planar and trigonal bipyramidal?
by Michael Cheng 1C
Mon Nov 06, 2017 12:46 am
Forum: Trends in The Periodic Table
Topic: Electron Affinity [ENDORSED]
Replies: 6
Views: 455

Re: Electron Affinity [ENDORSED]

What is the difference between electron affinity and electronegativity?
by Michael Cheng 1C
Mon Nov 06, 2017 12:44 am
Forum: Lewis Structures
Topic: Lewis Structures
Replies: 10
Views: 407

Re: Lewis Structures

Is the center atom when creating a lewis structure the least electronegative atom or the atom with lowest ionization energy?
by Michael Cheng 1C
Sat Oct 28, 2017 1:15 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Difference between subshell and orbital [ENDORSED]
Replies: 9
Views: 1158

Re: Difference between subshell and orbital [ENDORSED]

Can someone tell me the difference between a wave function and orbitals?
by Michael Cheng 1C
Sat Oct 28, 2017 1:08 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: electron spin quantum number (ms) [ENDORSED]
Replies: 4
Views: 304

Re: electron spin quantum number (ms) [ENDORSED]

How do you know if an electron will be spin up of spin down?
by Michael Cheng 1C
Fri Oct 20, 2017 11:03 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Electrostatic potential energy [ENDORSED]
Replies: 2
Views: 161

Re: Electrostatic potential energy [ENDORSED]

Yes the charges relate to the charges of the electrons of the atom
by Michael Cheng 1C
Fri Oct 20, 2017 11:01 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: s-,p-, d-, and f- orbitals
Replies: 7
Views: 416

Re: s-,p-, d-, and f- orbitals

I am confused. When is the d orbital less energy than the next s orbital? and when is d orbital greater energy?
by Michael Cheng 1C
Fri Oct 13, 2017 1:54 am
Forum: Properties of Light
Topic: Question 1.9
Replies: 3
Views: 217

Re: Question 1.9

Yes, the wavelength of a microwave is indeed 1mm.
by Michael Cheng 1C
Thu Oct 12, 2017 11:19 pm
Forum: Properties of Light
Topic: Balmer Vs. Lyman
Replies: 12
Views: 888

Re: Balmer Vs. Lyman

I am confused as to what n1 and n2 represent. What exactly does it symbolize?
by Michael Cheng 1C
Thu Oct 05, 2017 8:00 pm
Forum: SI Units, Unit Conversions
Topic: Formula Units
Replies: 7
Views: 359

Re: Formula Units

So does formula units only apply to ionic compounds?
by Michael Cheng 1C
Thu Oct 05, 2017 7:52 pm
Forum: SI Units, Unit Conversions
Topic: Sig Figs [ENDORSED]
Replies: 16
Views: 1886

Re: Sig Figs [ENDORSED]

How many sig figs is in 0.053?

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